If you kick the ball to where an opponent is then you haven't deliberately kicked the ball out have you? You've turned the ball over through poor skill. The reward is the ball back should the opponent be able to control it. Bad turnovers in your defensive half isn't going to be a recommended AFL tactic any time soon as far as I can tell.Here is a scenario.
Player from team A is under pressure in his defensive 50 - seconds remaining, less than a kick in it. To relieve the pressure he grubbers a hard, tumbling kick directly towards the boundary line where there is an opponent stationed.
The opponent has the choice to either try and take control of the ball - and possibly miscontrol the fast moving, tumbling ball - or let it go and win the free kick and a shot on goal to win the game.
The defensive player would win in this situation if the rule said that the opponent was obliged to try and keep the ball alive. Kicking the ball to the boundary would actually be an advantage to the defensive team if all the players had to do was make sure there was an opponent within touching distance of the ball. The pressure of keeping the ball alive would then go on to the opponent.
I just can't see it working. It is up to the person disposing of the ball to ensure that it stays in play, not the person closest to the ball.
Deliberate is a judgement call. If it's going to stay as a judgement call and not as a hard rule of 'last touch' then surely the umpires can make a judgement call on when the ball could've been kept in play and when it couldn't.
If there's no one in the area I'm not saying a player should hussle over to save the other team from a deliberate call, but if they are right there and shepherding the ball over they don't deserve a free kick. Toss in a boundary throw in.